My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX6420UK31+
- Part No.:
- MAX6420UK31+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6420UK31+.pdf
- Description:
- MAX6420 LOW-POWER, DUAL-VOLTAGE
- Quantity:
- Payment:
- Shipping:
Inventory:5,244
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX6420UK31+ from Maxim Integrated is a low-power, dual-voltage microprocessor reset supervisor IC with one factory-trimmed VCC reset threshold (3.075V typical) and one adjustable RESET IN input for monitoring secondary voltages down to 1.26V. It features an active-low open-drain RESET output, capacitor-adjustable reset timeout delay (275µs to >100ms), manual reset capability via external switch, and guaranteed reset validity down to VCC = 1V. It is used in battery-powered controllers and automotive ECUs requiring reliable dual-rail power monitoring.
For engineers reviewing the MAX6420UK31+ datasheet, MAX6420UK31+ pinout, MAX6420UK31+ application, or MAX6420UK31+ equivalent, key selection considerations include its dual-threshold architecture, SOT23-5 open-drain output compatibility with mixed-voltage µPs, capacitor-programmable timeout precision, and -40°C to +125°C automotive-grade operation.
Technical Context
The MAX6420UK31+ integrates two independent reset comparators: one laser-trimmed internal reference for VCC (3.075V ±2.5% over temperature) and one high-impedance RESET IN input with 1.255V–1.265V fixed internal threshold, enabling external resistor-divider programming of a second monitored voltage (e.g., 1.8V, 2.5V, 3.3V rails). Reset assertion occurs if either voltage falls below its threshold or MR is pulled low.
Its reset timeout is generated by a 240nA internal current source charging an external capacitor (CSRT) to a 0.65V ramp threshold; deassertion occurs after CSRT reaches that voltage, yielding tRP = (2.71 × 10⁶) × CSRT + 275µs. The open-drain RESET output supports pull-up to any voltage ≤5.5V, enabling logic-level translation across supply domains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 3.075V (typ), ±2.5% over -40°C to +125°C - ensures reliable brownout detection at nominal 3.3V systems |
| RESET IN Threshold | 1.26V (typ), 1.255V–1.265V - enables precise external voltage monitoring via resistor divider |
| Reset Timeout Range | 275µs to >100ms - set by 0–10nF capacitor on SRT pin; supports µP boot timing from fast logic to slow peripherals |
| Supply Current | 1.7µA (typ) at +25°C - enables multi-year battery life in portable/automotive always-on monitoring |
| Operating Temperature | -40°C to +125°C - qualified for under-hood automotive and industrial embedded environments |
| Output Type | Active-low open-drain - allows flexible pull-up to 1.8V, 3.3V, or 5V logic, isolating RESET domain from µP supply |
| Reset Validity | Guaranteed to VCC = 1V - ensures deterministic reset state during deep brownout recovery |
Pinout & Package
SOT23-5 package: 2.9mm × 1.6mm × 1.1mm body, gull-wing leads, RoHS-compliant lead-free finish (+ suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET | Open-drain reset output | Asserts low during fault; requires external pull-up; compatible with mixed-supply µPs up to 5.5V |
| 2 - GND | Ground reference | Primary return path for internal comparators and current source; must be low-impedance |
| 3 - RESET IN | Adjustable voltage monitor input | High-impedance (≤10nA leakage) node for resistor-divider; sets secondary rail threshold |
| 4 - MR | Manual reset input | Active-low; internally pulled up to VCC (20kΩ); debounced by timeout - no external RC needed |
| 5 - SRT | Reset timeout capacitor connection | 240nA precision current source; trace must be short and noise-isolated to avoid timeout drift |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneously supervises primary VCC (3.075V) and secondary rail (programmable via RESET IN) - eliminates need for two discrete supervisors |
| Capacitor-adjustable reset timeout | 275µs base + linear scaling with CSRT (0–10nF) - enables exact match to µP reset hold-time requirements without firmware changes |
| Open-drain RESET with wide pull-up range | Supports pull-up to 0–5.5V supplies - simplifies interface to legacy 5V µPs or modern 1.8V SoCs on same board |
| Ultra-low quiescent current | 1.7µA typical - reduces standby power in always-on automotive modules and medical sensors |
| Automotive-grade temperature range | -40°C to +125°C operation with full parametric guarantee - meets AEC-Q100 stress test expectations for ECU use |
Applications
| Automotive Engine Control Unit (ECU) | Portable Medical Sensor Hub |
|---|---|
Use Scenario: Monitors both 5V sensor supply and 3.3V MCU core rail in engine bay electronics exposed to thermal cycling and load dump transients. IC Role / Device Role / Timing Role: Dual-threshold supervisor asserting open-drain RESET to MCU upon either rail undervoltage; timeout set to 20ms to exceed flash programming lock time. Use Value: Prevents corrupted firmware writes during ignition cycling; open-drain output avoids level-shifting components in mixed-voltage PCB layout. | Use Scenario: Powers-on wearable glucose monitor with coin-cell battery, requiring guaranteed reset until both 3.0V analog front-end and 1.8V digital subsystem stabilize. IC Role / Device Role / Timing Role: Supervises VCC (3.075V threshold) and adjustable 1.8V rail (via 1MΩ/1.43MΩ divider on RESET IN); timeout set to 100ms for slow LDO settling. Use Value: 1.7µA supply current extends battery life beyond 2 years; guaranteed reset down to VCC = 1V prevents startup glitches during battery depletion. |
| Industrial PLC I/O Module | Battery-Powered Smart Meter |
Use Scenario: Embedded in DIN-rail mounted controller monitoring 24V field bus supply (via resistor divider) and 3.3V logic rail in harsh factory environments. IC Role / Device Role / Timing Role: Uses RESET IN to monitor scaled 24V (via 10MΩ/133kΩ divider → 3.075V), while VCC monitors local 3.3V; MR tied to service button. Use Value: Eliminates need for high-voltage supervisor IC; manual reset provides field-service recovery without power cycle. | Use Scenario: Ensures metering SoC boots only after both 3.6V Li-ion battery and 1.2V RTC backup rail are stable during cold-start. IC Role / Device Role / Timing Role: VCC pin monitors main battery (3.075V threshold); RESET IN monitors RTC rail (1.26V threshold scaled to 1.2V via divider); timeout set to 50ms. Use Value: Dual independent thresholds prevent false resets from RTC rail dip during battery insertion; -40°C to +125°C rating covers outdoor deployment extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-threshold reset applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS3808G33DBVR | Fixed 3.3V VCC threshold only; no adjustable RESET IN; push-pull output | Cannot monitor secondary rail; requires separate supervisor or resistor network for dual-rail | Select when only single-rail monitoring is needed and push-pull drive suffices |
| ADM6315-33D3ARTZ-RL | Fixed 3.3V threshold; no RESET IN; open-drain output; 200ms fixed timeout | Lacks programmability and dual monitoring; timeout not adjustable | Select for cost-sensitive designs where fixed 200ms timeout and single-rail supervision are acceptable |
Compared with TPS3808G33DBVR and ADM6315-33D3ARTZ-RL, the MAX6420UK31+ uniquely delivers factory-trimmed + user-adjustable dual-threshold supervision in one SOT23-5 package, enabling compact, flexible power sequencing without external components or firmware overhead.
Availability
MAX6420UK31+ is available at Aetrix Electronics and suitable for automotive engine control units, portable medical sensor hubs, industrial PLC I/O modules, and battery-powered smart meters requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6420UK31+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing applications.
The MAX6412–MAX6420 product line was designed specifically for ultra-low-power, capacitor-programmable reset supervision in space-constrained, thermally demanding systems requiring dual-rail voltage monitoring and automotive-grade reliability.
FAQ
What is the exact VCC reset threshold voltage for MAX6420UK31+?
The MAX6420UK31+ has a factory-trimmed VCC reset threshold of 3.075V (typical), with a guaranteed range of 2.998V to 3.152V at +25°C and ±2.5% tolerance over -40°C to +125°C. This corresponds to the "31" suffix per Table 1 in the datasheet and is laser-trimmed for precision without external calibration.
How do I calculate the external capacitor value for a 50ms reset timeout with MAX6420UK31+?
Use the formula tRP = (2.71 × 10⁶) × CSRT + 275µs. For tRP = 50ms (0.05s), solve: CSRT = (0.05 − 0.000275) / 2.71 × 10⁶ ≈ 18.3nF. A standard 18nF ceramic capacitor (low-leakage, X7R/C0G) yields ~49.8ms timeout. Confirm with oscilloscope measurement due to ±15% capacitor tolerance.
Can MAX6420UK31+ monitor a 1.8V rail as the secondary voltage?
Yes. Connect a resistor divider between the 1.8V rail and GND, feeding the junction to RESET IN. With VRST = 1.26V, use R2 = 1MΩ and R1 = 1MΩ × (1.8V / 1.26V − 1) ≈ 429kΩ. The MAX6420UK31+ will assert RESET when the divided voltage at RESET IN falls below 1.26V - i.e., when the 1.8V rail drops below ~1.8V × (1.26V / 1.26V) = 1.8V.
Does MAX6420UK31+ require an external pull-up resistor on the RESET pin?
Yes. Because MAX6420UK31+ features an open-drain RESET output, an external pull-up resistor is mandatory. Select value based on rise time and bus capacitance: 10kΩ for 3.3V logic (ensuring <1µs rise with ≤50pF load) or 4.7kΩ for 5V systems. Pull-up voltage may be any supply from 1.8V to 5.5V, independent of VCC.
Is MAX6420UK31+ qualified for automotive applications?
Yes. The "+" suffix denotes lead-free RoHS compliance, and the device is fully specified from -40°C to +125°C with guaranteed parameters across that range. While not explicitly AEC-Q100 certified in this datasheet, its temperature rating, transient immunity, and production screening align with automotive ECU requirements; consult Analog Devices for qualification status documentation.
MAX6420UK31+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- -
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 3.075V, Adj
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 3ms Minimum
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6420UK31+ FAQ
1.How can I place an order for MAX6420UK31+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6420UK31+ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX6420UK31+ reliable?
The price and inventory of MAX6420UK31+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6420UK31+ is usually 5 days.
3.What payment methods are accepted for MAX6420UK31+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6420UK31+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6420UK31+?
MAX6420UK31+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6420UK31+ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX6420UK31+?
For technical support, including MAX6420UK31+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6420UK31+ requirements.
6.How does Aetrix verify that MAX6420UK31+ is sourced from the original manufacturer or authorized distributors?
All MAX6420UK31+ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX6420UK31+ meets industry standards.
7.What is the process for return or replacement of MAX6420UK31+?
All MAX6420UK31+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6420UK31+, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX6420UK31+ part is unused and in its original packaging.
Return procedure for MAX6420UK31+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6420UK31+ Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
